Portable System Controller

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The DS1677 portable system controller is a circuit that incorporates many of the functions necessary for low-power portable products integrated into one chip. The device provides a real-time clock (RTC), NV RAM controller, microprocessor monitor, power-fail warning, and a 3-channel, 8-bit analog-to-digital converter (ADC). Communication with the DS1677 is established through a simple 3-wire interface.

The RTC provides seconds, minutes, hours, day, date, month, and year information with leap year compensation. The RTC also provides an alarm interrupt. This interrupt works when the DS1677 is powered by the system power supply or when in battery-backup operation so the alarm can be used to wake up a system that is powered down.

Automatic backup and write protection of an external SRAM is provided through the VCCO and active-low CEO pins. The backup energy source used to power the RTC is also used to retain RAM data in the absence of VCC through the VCCO pin. Active-low CEO, the chip-enable output to SRAM, is controlled during power transients to prevent data corruption.
DS1677: Block Diagram DS1677: Block Diagram Enlarge+

Key Features

  • Provides Real-Time Clock
    • Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap Year Compensation Valid Up to 2100
    • Power Control Circuitry Supports System Power-On from Day/Time Alarm
  • Microprocessor Monitor
    • Halts Microprocessor During Power-Fail
    • Automatically Restarts Microprocessor After Power Failure
    • Monitors Pushbutton for External Override
    • Halts and Resets an Out-of-Control Microprocessor
  • NV RAM Control
    • Automatic Battery Backup and Write Protection to External SRAM
  • 3-Channel, 8-Bit ADC
  • Simple 3-Wire Interface
  • +5.0V Operation
  • 1.25V Threshold Detector for Power-Fail Warning
Part NumberInterfaceVSUPPLY
Time Keeping Current
Memory TypeTime of Day AlarmsFunctionsPackage/PinsBudgetary
typSee Notes
DS1677 3-Wire53006None1
NV SRAM Control
$5.04 @1k
See All Timekeeping & Real-Time Clocks (77)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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